Roundup of Global Volcanic Activity – Ongoing Activity for the Week 4 August – 10 August 2021
Aira – Kyushu (Japan) : JMA reported that incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible at night during 2-9 August. Very small eruptive events were recorded during 2-6 August. The sulfur dioxide emission rate was relatively elevated at 1,500 tons per day on 4 August.
Asamayama – Honshu (Japan) : On 6 August JMA lowered the Alert Level for Asamayama to 1 (on a scale of 1-5), noting that the number of shallow volcanic earthquakes had been decreasing, sulfur dioxide gas emissions had been low, and deformation on the W flank had stabilized.
Copahue – Central Chile-Argentina border : SERNAGEOMIN and SEGEMAR reported increased activity at Copahue during 9-10 August, characterized as increased gas emissions, ash emissions, and crater incandescence. During the morning of 9 August gas-and-steam emissions increased and sulfur dioxide flux was as high as 7,200 tons per day. Crater incandescence was visible in nighttime webcam views and was intense during the early hours of 10 August. An ash plume rose 300 m above the crater rim and drifted N and NNW. Seismicity remained stable; data suggested no rising magma.
Dukono – Halmahera (Indonesia) : PVMBG reported that during 3-4 and 6 August white-and-gray ash plumes from Dukono rose 100-500 m above the summit and drifted E and W. Weather conditions prevented visual observations during 5 and 7-10 August.
Ebeko – Paramushir Island (Russia) : According to volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, explosions during 29 July, 1 August, and 3-5 August produced ash plumes that rose as high as 2.5 km (8,200 ft) a.s.l. and drifted S and SE. A thermal anomaly was identified in satellite images on 1 August.
Etna – Sicily (Italy) : INGV reported continuing activity at Etna’s summit craters during 2-8 August, mainly from the Northeast Crater (NEC) and the Southeast Crater (SEC). Gas emissions rose from Voragine Crater and from two active craters in Bocca Nuova. A series of discontinuous ash emissions from NEC began at 1350 on 4 August and lasted about two hours. An ash plume rose to 1.8 km (6,000 ft) a.s.l. and drifted NE. Similar but less intense ash emissions were visible on 5 August. The reddish mostly fine-grained material emitted from NEC was erupted when no thermal anomalies were present in the crater, suggesting that they were the result of landslides rather than eruptive activity. Strombolian activity began at SEC at 2057 on 7 August and was characterized by isolated explosions and the ejection of incandescent material beyond the crater rim; activity ceased during the night. An explosion at 2056 on 8 August was followed by the resumption of Strombolian activity at 0030 on 9 August. Incandescent material was again ejected beyond the crater rim and an ash plume drifted SE.
Fuego – Guatemala : INSIVUMEH reported that 4-13 explosions per hour were recorded during 3-10 August at Fuego, generating ash plumes as high as 1.1 km above the crater rim and shock waves that often rattled buildings around the volcano. Ash plumes mostly drifted as far as 15 km W and SW, causing daily ashfall in several areas downwind, including Morelia (9 km SW), Panimaché (8 km SW), Santa Sofía (12 km SW), Yucales (12 km SW), El Porvenir (8 km ENE), Finca Palo Verde, Sangre de Cristo (8 km WSW), and San Pedro Yepocapa (8 km NW). Block avalanches descended the Ceniza (SSW), Seca (W), Trinidad (S), Taniluyá (SW), Las Lajas (SE), and Honda drainages, often reaching vegetated areas. Explosions ejected incandescent material 100-400 m above the summit during 4-6 and 9-10 August. At 1700 on 6 August a lahar descended the Las Lajas drainage, carrying fine material along with tree branches and blocks 1-2 m in diameter.
Karymsky – Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was identified in satellite images during 29 and 31 July, and 1, 2, and 4 August. Weather clouds prevented satellite observations on the days in between as well as during 5-6 August. Gas, steam, and ash plumes from explosions rose 2.5 km (8,200 ft) a.s.l. and drifted 75 km SE during 1 and 4-5 August.
Lewotolok – Lembata Island (Indonesia) : PVMBG reported that the Strombolian eruption at Lewotolok continued during 3-10 August. Daily white, gray, and sometimes black plumes rose as high as 1.5 km above the summit and drifted in multiple directions. Banging noises associated with eruptions were reported almost daily.
Merapi – Central Java (Indonesia) : BPPTKG reported that the lava dome just below Merapi’s SW rim and the lava dome in the summit crater both remained active during 30 July-5 August. The SW rim dome volume was an estimated 1.895 million cubic meters and about 3 m tall. A total of seven pyroclastic flows descended the SW flank as far as 2 km and as many as 84 lava avalanches traveled a maximum of 2 km SW. Multiple pyroclastic flows traveled 2-3 km down the SW flank on 8 August and ash plumes rose 1 km above the summit. According to a news article ashfall was reported in several local communities. Pyroclastic flows traveled up to 3 km down the SW flanks multiple times during 9-10 August. BNPB noted that a small fire on the SW flank, 2.5 km from the crater, was set by ejected incandescent material; the fire burned an area of only 30 square meters during 25-26 August.
Popocatepetl – Mexico : CENAPRED reported that each day during 4-10 August there were 30-92 steam-and-gas emissions from Popocatépetl. The plumes drifted mainly W and some contained ash. A minor explosion was recorded at 0652 on 4 August. At 2137 on 6 August a moderately-sized explosion produced a plume, thought the height and drift direction were obscured by weather conditions. Incandescent fragments ejected from the crater were seen falling on the flanks not far from the crater rim. Weather conditions again prevented views of an explosion at 0258 on 8 August.
Raung – Eastern Java (Indonesia) : PVMBG reported that neither explosive nor effusive activity had been recorded at Raung since February, and emissions were not observed during 1 July-8 August. Seismicity had declined and deformation data indicated a trend of deflation.
Santa Maria – Guatemala : INSIVUMEH reported that during 4-10 August daily explosions at Santa María’s Santiaguito lava-dome complex generated ash plumes that rose as high as 1 km above the summit and drifted as far as 7 km SW and W. Incandescence from the complex was occasionally visible at night. Collapses of blocky lava from Caliente dome sent avalanches down the S, SW, and W flanks, often reaching the base, and caused minor ashfall mostly on the volcano’s flank. Ashfall was also reported in San Marcos (8 km SW), Loma Linda Palajunoj (6 km WSW), and surrounding farms during 3-4 and 8-9 August. Heavy rainfall on 7 August caused a lahar to descend the Tambor River, carrying branches, tree trunks, and blocks up to 3 m in diameter.
Semeru – Eastern Java (Indonesia) : Semeru continued to erupt during 4-10 August. Inclement weather often prevented visual observations, though during 4-7 August avalanches of lava from the end of the flow in the summit crater were seen traveling 200 m SE down the Kobokan drainage. Gray-and-white plumes rose 500 m above the summit and drifted SW during 6-7 and 9 August.
Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 30 July-6 August.
Sinabung – Indonesia : PVMBG reported that on most days during 3-10 August white gas-and-steam plumes from Sinabung rose as high as 500 m above the summit and drifted in multiple directions. Avalanches of lava traveled 500-700 m down the E and SE flanks during 4-7 August.